Update: Leptospirosis has increased in dogs in the past 10 to 20 years. The disease is transmitted by exposure to urine of an infected animal, usually wildlife, and can cause potentially fatal kidney or liver damage. In this study, researchers from Purdue University are investigating the frequency and distribution of leptospirosis in dogs in the United States and will determine the specific bacterial strains of Leptospira that pose the greatest risk in the development of severe clinical disease. Researchers are making excellent progress in mapping out the distribution of leptospirosis and have evaluated more than 30,000 blood samples submitted to a commercial laboratory for testing over a seven-year period. So far, after examining preliminary data, the researchers have identified two significant regional and temporal outbreaks of the disease in the United States. Over the next six to nine months, they will focus on collecting blood and urine samples to characterize different bacterial strains of the disease. Identifying common proteins among clinically important strains will greatly improve vaccine development and cross-protection. Researchers will also use the samples collected to evaluate the antibody responses of vaccinated and naturally infected dogs with the goal of developing future vaccines and better diagnostic tests.